Water Ice On Mars

cathector sends along a story from SpaceWeather.com on the discovery of water ice on Mars. "Scientists have figured out the mysterious white substance unearthed by NASA's Phoenix lander on Mars. It's frozen water. The breakthrough came last week when Phoenix's stereo camera caught the substance in the act of disappearing. Bathed in martian sunlight for four days, the white substance sublimated — i.e., it transformed from solid to gas without passing through the liquid state. This is how water behaves on Mars.... Some readers have asked, how do we know the white substance is not frozen CO2 (dry ice) instead of frozen water? Answer: Phoenix's landing site is too warm for dry ice. The average daily temperature is about -70 F while dry ice requires temperatures lower than about -109 F." The animated GIF showing the ice sublimating is pretty nice too.

Comments

Re:Martian ice is really big news, folks!

[Anonymous Coward]

Neat!

Sorry - it's a Scotch joke.

I know

[Anonymous Coward]

Pretty much anything can sublimate under the proper conditions. But when you say "a white solid that sublimates at -70 degrees F and martian surface pressure and is found in macroscopic quantities naturally" you narrow down the field quite a bit. In this case, to exactly one reasonable possibility.

Yep, Vodka.

Re:average daily temperature

[Solandri]

Could we have this important information in units used by, I don't know, the rest of the world?

Hah! With this announcement, NASA has predicated that Fahrenheit is now used on the surface of two worlds, thus re-establishing its dominance over that other temperature unit which is only used in part of one world. We will wrest control of this universe back from you metric heathens, even if we have to do it one planet at a time!